A moving video called a moving photo may be categorized into two types of TV video and theater screening video in shooting and production. First of all, in case of the theater screening video taken using a film, typical still photos are taken continuously and then displayed in accordance with a time sequence. In this case, it is easily noted that each cut of the video becomes a still video. However, since the video broadcasted through TV includes two fields not a whole photo of one cut, these fields should be combined with each other to allow a user to see a whole photo. In this case, various reasons may exist. Since TV transmission technique and performance of the cathode ray tube are not good in the early stage, a very short time for emitting light by stimulating a fluorescent material through a cathode ray is big reason. In case of NTSC scheme, since 30 sheets of frames (29.97 fps) are required for 1 second, the video should remain on the cathode ray tube for at least 1/30 seconds or more until next frame is displayed after one frame is displayed. However, since the cathode ray tube of the early stage does not support this technique, an expedient method for splitting one frame into two fields and interlacing them is used. In this way, the video could be transmitted by a cathode ray tube and transmission scheme of low performance. However, a drawback occurs in that movement of fast scene or complex video cannot be displayed in detail. This interlace scan scheme has been applied to most of TVs up to now, and most of all videos have been shot, edited and broadcasted in accordance with the interlace scan scheme. Meanwhile, the theater screening video shot by a film is displayed by 24 sheets of images (24 fps) per second progressive in due order, wherein the 24 frames indicate a sheet of photo which is not split. Therefore, the theater screening video has advantages in that a clearer image may be displayed and details are not lost even in case of fast movement.
There are a progressive scan scheme and an interlace scan scheme. A main example of the progressive scan scheme may include computer monitor or digital TV such as PDP or LCD. This progressive scan scheme displays all horizontal lines of video in one frame at one time. On the other hand, TV currently used by most of people displays only half of a horizontal line in one image frame when displaying one image regardless of NTSC scheme or PAL scheme. This scheme will be referred to as the interlace scan scheme. That is, the interlace scan scheme displays an image on a screen by splitting one frame into two fields (top/bottom, upper/lower/odd/even, etc.) and alternately displaying the fields in due order.
One of those most closely related to a 3:2 pulldown progressive scan scheme is a movie produced by a film. This is because that an original source of most of all DVD movie titles recently released is a movie produced by a film. Unlike NTSC TV, a movie is produced by 24 frames per second. DVD may be produced directly by original image of 24 frames in the same manner as original movie. However, since most of display equipments such as TV currently used are interlace type equipments, DVD should practically be produced by the interlace scan scheme in accordance with such an interface. At this time, a task for switching a film of 24 frames to a video of 60 fields will be referred to as 3:3 pulldown or telecine. This may be summarized in such a manner that five video frames are produced by four films by adding one field per two film frames. 3:2 pulldown means that three fields are made by a first frame and two fields are made by a second frame.
Recently, in accordance with the development of display technology, a progressive type display device has appeared, whereby studies of a method for restoring 3:2 pulled-down video will be required.